The Xbox Live Indie marketplace is honestly one of the Xbox's coolest features, letting small upstart developers program games for the console, without having to find a publisher or work their way through the complicated Xbox Live approval process. Though this has led to an overabundance of crap filling the Indie marketplace, at least it's well-intentioned crap (as is the case with this game I worked on…), and hopefully the removal of some previous restrictions on Indie content will make it even better.
Before, games were limited to a size of just 150MB. Now, developers are allowed a full 500MB of content, meaning higher-resolution textures, higher-quality audio files, and perhaps games that look more complex than your average Flash clone. Pricing has also been adjusted. Previously, any title larger than 50MB needed to be priced at either 240 or 400 Microsoft points (about $3/$5). With 80 points as the competitive price point most developers strive towards, Microsoft will now allow any game under 150MB to qualify for budget pricing.
Finally, developers can now sell up to twenty games on the service, whereas before they were limited to ten. Time to get programming fellas!